Drier and separator for sand and the like



Aug. 17 19261 F. E. GREENE DRIER AND SEPARATOR FOR SAND AND THE LIKEFiled August 50 1922 '1 m f 25.3.1.6 A "\Q Patented Aug. 17, 1926.

FRED IE. GREENE, OF OAKLAND, CALIFORNIA.

DRIER AND SEPARATR FOP SAND AND THE LIKE.

Application filed August 3G, 1922.

This invent-ion relates to the separation and drying of sand, crushedrock7 aggregate and the like, and has for its object to sepa rate thematerials simultaneously with the heating and drying thereof.

In the making of paving material and the like the specifications usuallyrequire eXactness as to the quantities of the different sizes of sand,crushed rock, etc. The practice heretofore has been to first heat anddry the material in aggregate form and thereafter separate the same intoits various mesh sizes so that the correct proportions of each size maybe introduced in the mixture. his separate drying and grading not onlyincreases the time and labor in preparing the material, but also permitsthe heated material to cool during the subsequent operation ofseparating the same. I find that better results are obtained where thesand.` crushed rock, etc. are hot when broughttogethcr with the hotasphalt or other binder.

One form which my invention may assume is exemplified in the followingdescription and illustrated in the accompanying drawing. in which` Fig.1 shows a central, longitudinal. sectional view of a device embodying myinvention. 1

Fig. 2 shows a similar view of the delivery end of the device.

Fig. 3 shows a cross sectional view taken near the center of the device.

The mechanism herein shown comprises a rotatable cylii'idrica-l shell 10having peripheral tracks 11 operating upon rollers 1Q. Carriedconcentrically within the shell by means of radial spokes 13 are aplurality of cylindrical screens designated respectively 14, 15 andl,each of a didier-ent mesh size. the coarsest screen being near thecenter of the shell and the liner screen towards the outside. One end ofthe shell is closed by means of a plate 17 and extending through anopening therein is a feed hopper 18 which discharges on to the innermostscreen. The shell is slightly inclined downwardly from the feed end sothat the material willv gradually work its way towards the opposite endwhen the shell is rotated. rlhe coarser material will remain on theinside screen and the liner material will pass on to the surroundingscreens. To assist in lifting and agitating the materiales the shell isrotating the interior of each screen and of the shell is provided withfins or baiies 19 Serial No. 585,251.

inclined in the direction of rotation of the shell.

The end of the shell and of the sore s opposite the feed hopper extendinto a. hous- 20, the shell projecting only a slight distance thereinand the screens from the outer to the inner screens being projectedsuccessively farther' therein. Underneath the discharge cnd of eachscreen and of the shell and arranged within the housing is deliveryconduit E21, the conduits or chutes for the finer material preferablydelivering to one side and the conduits or chutes for the coarsermaterial delivering to the other side, as shown in Fig. 9

`Extending through the end wall of the housing 20 and into the shell isan openended fire tube 22, which is supported by the spokes 13 withinthe innermost screen. The' end of the tube adjacent the housing receivesa burner and the opposite end of the tube terminates short .of the feedend of the screen. In front of the latter end is a cone-shaped delector211 which serves to prevent the sand, crushed rock, etc. from enteringthe tube and also directs the heated air and iame outwardly so as toallow it to return in the opposite direction through the screens whereit discharges through flue or chimney arranged upon the housing` 20. Thefire tube rotates with the shell and has on its periphery radial fins orbaffles 26 forming pockets to catch the sand or crushed rock that islifted by the inclined Hns or baffles onthe interior of the surroundingscreen. y

The operation of the, described structure briefly is as follows: Amixture of sand and crushed rock or aggregate is fed on to the innermostscreen through the hopper 18 and the shell is rotated by any suitablemeans. The material is picked up by the inclined fins or baffles andcarried partially around, and at the same time is urged towards theopposite end of the screen, due to the inclination of the shell. Thecoarser particles are retained on the inside screen, while the finerparticles find their way on to the surrounding screens. By the time thematerial reaches the opposite end a complete segregation has beeneffected, and the different grades are delivered into separate dischargechutes. The burner being in op- 'eration will cause the material to bedried and heated during its passage lthrough the screen device. Theheating action is assisted by the passing ot the flame and the heatedair longitudinally through the tire tube and returning it diagonallythrough all the screens. inasmuch as vthe burner is arranged at thedischarge end oli' the device the material ivill be gradually heatedbeiiore reaching the hottest part ot' the device. The action of theinclined tins, is to lift and carry the material up to a point Where itwill iiall off and pass through the returning hot blast, rEhe materialon the inner screen Will .be dropped on to the tire tube and the radiallins on the latter will retain it and carry it around tor aboutone-third oitl a turn so that the full eilect of the heat is impartedthereto.

The material is thus separated and heated anl can be mixed with asphaltor other binder in the desired quantities While still het.

Various changes in the construction and arrangement ot the several partsherein shoivn and described may be employed without departing 'from thespi `it ot my invention as disclosed in the appended claims.

Having thus described my invention, what I claim and desire to secure byLetters Patent is l. A combined separating and heating device fornaterial of the character mentioned comprising a rotating cylindricalshell, a plurality ol' screens carried thereby and arrangedconcentrically therein of graduated mesh decreasing in size from thecenter to the outside, means lor feeding material on to the innermostscreen at one end, individual delivery means at the opposite end of eachscreen, a lire tube extending axially through the innermost screen andterminating adjacent the feed end thereof, a burner in the opposite endof the tube, and neans Yfor directing the heated air from the nre, tubealong the length of the screens and means to rotatably support theshell.

2. A combined separating and heating device for material of thecharacter mentioned comprisii'ig a rotatingl cylindrical shell, aplurality oit screens arranged concentrically therein oi' graduated meshdecreasing in size from the center to the outside, means tor feedingmaterial on to the innermost scr en at one end, individual deliverymeans at the opposite end of each screen, a tire tube extending axiallythrough the innermost screen and terminating adjacent the reed endthereof, a burner in the opposite end ot the tube, a detlector in rontot the discharge end-ot' the tube for directing the heated air on to thescreens and a ll e adjacent the discharge end of the shell 'tor takingoil the heated air` 'l combined separating and heating device 'formaterial ot the character mentioned comprising a rotating cylindricalshell, a plurality ot screens arranged concentrically therein ofgraduated mesh insing in size trom the center to the outside, means foriieeding material on to the innermost screen at one end, individualdelivery screen, a lire tube extending axially through the 'inermostscreen and terminating adjacent the reed end thereoi', a burner in theopposite end ot' the tube, and means for di- 1ect-ing the heated airfrom the tire tube along the length oit the screens, each ot saidscreens being provided Wit-h bailles on its interior 'tor agitating andlifting the material and pockets arranged on said fire'tube 'forreceiving the material vdropped `from the Fins of the surroundingscreen.

4l, combined separating and heating device ttor material oi the classmentioned comprising a rotating cylindrical shell, a plurality ofconcentric screens therein of graduated mesh decreasing in size from thecenter to the. outside, means for feeding material on to the innermostscreen at one end, a stationary housing at the opposite end of the shelland screens, delivery devices arranged on said stationary housing, one'lor each of said screens, a lire tube extending axially through theinnermost screen and rotating with said shell and screens, a burnerarranged in the end o't` said lire tube adjacent the housing, a chimneyon said housing, and means adjacent the discharge end the fire tube 'fordirecting the heated air from the burner on to the screens to allow itto return in the opposite direction to the chimney.

' FRED E. GREENE.

n'ieans at the opposite end of each

